Ben 10: Alien Force Season 2 Episode 5 — "Undercover"

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The stakes of the planetary conflict scale higher in Ben 10: Alien Force Season 2 Episode 5, "Undercover." This episode brings back a brilliant, familiar face from the original series, serving as a direct connection to Ben's past while revealing the terrifying scope of the Highbreed’s engineering projects on Earth.

When the team discovers that the DNAliens have abducted a highly gifted young human mind, they are forced to stage a high-risk infiltration mission. They quickly realize the hostage is none other than Cooper Daniels, the technopathic kid genius who helped Ben in his youth. Now undergoing a massive growth spurt, Cooper is being forced to use his unique gifts against his will to construct a massive, mysterious gateway for the alien invaders.

“They're making him build something huge. If Cooper's tech-powers are putting it together, whatever that arch does, it can't be good for Earth.”

Episode Summary

The narrative kicks off as Ben, Gwen, and Kevin investigate a spike in alien activity inside an abandoned, heavily fortified military base. To their shock, they discover the DNAliens have set up a massive construction site overseen by a strict Highbreed Commander. Using stealth, the trio penetrates the perimeter and finds Cooper Daniels being kept in a high-tech cell, forced under duress to engineer a colossal metal archway.

Cooper explains that his rare technopathic ability—the power to mentally perceive, manipulate, and rebuild any mechanical structure—makes him the ultimate asset for the Highbreed. If he refuses to comply, the aliens threaten to infect him with a Xenocyte parasite. Kevin and Ben hatch an escape plan, but their cover is blown, triggering a chaotic base-wide alert as security forces converge on their position.

An explosive battle erupts within the facility. Ben leads the offensive charge, cycling through powerful forms including Big Chill to freeze structural entryways and Humungousaur to match raw strength against the elite Highbreed commander. Meanwhile, Kevin absorbs specialized compound alloys to shield Cooper, and Gwen deploys aggressive mana energy shields to hold back waves of oncoming DNAliens.

In the final sequence, Ben utilizes the elastic, density-shifting powers of Goop to slide into the core machinery, systematically destroying the energy cells powering the construction grid. Cooper uses his lingering mental connection to the tech to overload the archway, causing the entire military installation to collapse into ruins. Though the facility is completely obliterated, the Highbreed commander safely retreats into the night, leaving the heroes to contemplate the true purpose of the destroyed warp gate.

Themes & Character Development

The Price of Genius: Cooper's narrative arc shows the dark side of harboring extraordinary power. His unique technopathic gift makes him a constant target for galactic factions who wish to exploit his mind for warfare.
Physical and Emotional Growth: Cooper's dramatic physical change mirrors the transition from childhood to adolescence. He struggles with newfound teenage insecurities, particularly his immediate, awkward crush on Gwen.
Industrial Sabotage: The episode transitions the team from reactive neighborhood vigilantes into a structured, proactive military strike force capable of shutting down advanced alien production lines.

Production Details

First Aired: November 13, 2008
Created By: Man of Action (Duncan Rouleau, Joe Casey, Joe Kelly, and Steven T. Seagle)
Written By: Adam Beechen
Directed By: Butch Lukic
Produced By: Cartoon Network Studios
Art Style: Dark, industrial military aesthetics contrasted sharply with the vibrant lime-green silhouette of Goop and bright pink magenta energy trails
Voice Cast:
- Yuri Lowenthal as Ben Tennyson / Big Chill / Humungousaur / Goop
- Ashley Johnson as Gwen Tennyson
- Greg Cipes as Kevin Levin
- Corey Padnos as Cooper Daniels
- Dee Bradley Baker as the Highbreed Commander / DNAliens

Fun Facts & Trivia

Did You Know?

This episode marks Cooper Daniels' very first appearance in the *Alien Force* sequel series. He was originally introduced as a small child in the original 2005 series finale movie, *Ben 10: Secret of the Omnitrix*.
Cooper’s drastic growth spurt and sudden muscle mass shocked the characters and fans alike; Kevin spends a good portion of the episode making jokes about how much bigger Cooper got.
The giant metal structure Cooper is forced to construct is later revealed to be a critical component of a localized Highbreed "Jump Gate," intended to bring the main invasion fleet directly to Earth.
When Ben transforms into Goop to destroy the facility, he demonstrates an advanced application of the alien's anti-gravity projector, using its localized energy field to manipulate heavy control levers.
Writer Adam Beechen intentionally added a comedic love triangle element, using Cooper's overt infatuation with Gwen to annoy and ignite jealousy in Kevin.

Legacy & Impact

"Undercover" serves as a vital bridge connecting original series continuity to the escalating narrative of the Highbreed war. By reintroducing Cooper, the writers honored long-standing lore while showing how the global alien threat was actively uprooting the lives of former allies across the globe.

The destruction of the base provided a major tactical victory for Ben's team, but the structural blueprints of the mysterious archway left an ominous warning. It proved that the Highbreed invasion wasn't a distant threat, but a meticulously engineered trap that was rapidly nearing completion right under humanity's feet.